What better time to revisit standards for industrial wireless applications than right now? The WirelessHart standard, published in September 2007 by the Hart Communication Foundation, and blessed by the International Electrotechnical Commission (IEC, as publicly available specification IEC/PAS 62591Ed. 1) exactly a year later, has moved into the industrial world (see “WirelessHart Moves Forward ”). More recently, in April 2009, the International Society of Automation’s ISA100 Standards Committee on Wireless Systems for Automation voted to approve the ISA100.11a “Wireless Systems for Industrial Automation: Process Control and Related Applications” standard.

Some steps remain for ISA100.11a, which took the longest to arrive, but most of the hard work is over. Final comments gathered during the voting are going to be assessed, possibly resulting in some tweaks. Then, the ISA Standards and Practices Board must officially approve the standard, which is still technically a draft. According to those in the know, that could happen as soon as August of this year.

The follow-on steps will happen when the American National Standards Institute (ANSI) ratifies and publishes the standard, which could be relatively quickly. Plans are to take the standard global, so the IEC will duly deliberate, and in its own good time pronounce it yea or nay.

This business of making standards is a slow one, and time has indeed passed. ISA announced the formation of the ISA100.11 work group in May of 2006. Time is required to reach consensus around something that has hundreds, if not thousands, of technical details. April’s ISA100.11a yes-vote garnered 81 percent of the more than 600 voting members. Among these were 23 of the 24 end-user members.

 “Actually, while it’s an exciting announcement, looking back on the final vote, it was sort of a non-event,” says Cliff Whitehead, manager of strategic development at automation vendor Rockwell Automation Inc., Milwaukee, and an ISA100.11a committee member. “That doesn’t mean it was a foregone conclusion, but the previous ballot on the draft last October failed by only one vote. The changes that were made since that vote must have been pretty persuasive—65 percent voted ‘for’ in October, but this time, it was 80-plus percent.”

The dynamic nature of standards building is highlighted by this final, rolling record of agreement. Asked how consensus can prevail among technologists—who usually know their minds and are not quick to change them—Whitehead explains, “First of all, there is a detailed roadmap from ISA and ANSI that guides the whole process. It is essentially parliamentary procedure, which means that everyone theoretically has a chance to have his or her say.”

Whitehead delineated some of the procedural facets that helped smooth the process. First, the role of the leader of each work group was “less about participation and creation, and more about coordination. The objective was to hear all the sides of the issues—or at least, the biggest aspects—and maintain order.”

The concept? Let everyone have a say, and ideas find their own level. In reality, it does not work quite so smoothly, but eventually, rough edges are polished and the better concepts work their way to the top. Through it all, documentation and accountability help keep an even keel. “The leaders are kept accountable for steady progress,” Whitehead explains. “Participants were held accountable for good behavior as well. Everything was documented, and there was a very active Web site for work and document sharing.”

The latter was especially important because, as he says, “We all had our day jobs, and the personnel in attendance at any given meeting or teleconference could be different from the next get-together. We had to keep tabs on what had happened and what was on the table for discussion.”

The documentation itself, Whitehead says, was impressive. “The highly technical editors involved should take pride in their work. The tech committee, editors and authors really did their due diligence in going through literally thousands of comments from committee members, reviewers, vendors and users. The objective behind all the words and graphics was to set up a clear roadmap for equipment builders and end-users. Like everything else, this was and is an iterative process. We’ll see further revisions as everyone gets down to cases and uncovers areas that need more clarification.”

A rational process is fine, but perhaps more important was the basic technology and information gathered under the guidance and control of that process.

“There were many, many people who provided input,” agrees Dave Kaufman, wireless business manager for vendor Honeywell Process Solutions and fellow .11a committee member in Phoenix. ...